Download Lab 24 Dissection Steps:

Lab 24 Dissection Steps:
❏ On the LEFT half of the head (or whichever side has had the zygomatic arch removed)
identify the ​orbit ​(conical cavity containing the eyeball) and the ​periorbita
❏ Transect and reflect the orbital ligament from the lateral aspect of the orbit​. ​Identify the
lacrimal gland ​just medial to the orbital ligament.
❏ Incise the periorbita longitudinally on its lateral side and reflect it to reveal the
underlying muscles.
❏ Attempt to identify
​
the​ levator palpebrae superioris m.
❏ Identify the ​rectus muscles: dorsal, ventral, medial & lateral
❏ In between the rectus muscles identify the four fascicles of the ​retractor bulbi m.
❏ Identify the ​ventral oblique m.
❏ Roll the dorsal aspect of the eyeball laterally to expose/identify the ​dorsal oblique m.
❏ As the dorsal oblique passes rostrally, it narrows to a long tendon that
passes through a cartilaginous plaque called
​​
the ​trochlea. Identify the
trochlea as you detach the eyeball to roll it laterally.
❏ Leave the ​bulbus oculi (eyeball)​ in the orbit as you complete the following dissection:
❏ Identify the structures of the ​external fibrous coat:
❏ cornea
❏ sclera
❏ limbus (corneoscleral junction)
❏ Observe the ​optic nerve​ on the posterior surface of the globe by
separating the rectus and retractor bulbi muscles.
❏ Identify the structures of the ​middle vascular coat (uvea) ​by using a
sharp scalpel blade to make a sagittal cut through the eyeball from
anterior to posterior poles. Make another cut near the first to create a
wedge piece of the wall (like a slice of pie) of the eyeball and reflect it.
Identify the following​:
❏ iris
❏ pupil
❏ choroid
❏ Attempt to identify the ​tapetum lucidum
❏ ciliary body
❏ ora serrata (junction of choroid & ciliary body)
❏ ciliary processes
❏
zonule (zonular fibers)
❏ Identify the ​lens
❏ Identify the ​anterior chamber & posterior chambers​ and the ​aqueous
humor ​(liquid inside the chambers)
❏ Identify the ​vitreous chamber​ and the ​vitreous body ​(gelatinous
substance inside the chamber)
❏ Identify the structures of the ​internal coat (retina)
❏ optic disc
❏ fundus
❏ On the RIGHT half of the head, dissect the following veins (but be sure to spare the
nerves that are in the same dissection field!):
❏ external jugular v.
❏ linguofacial v.
❏ lingual v.
❏ facial v.
❏ maxillary v.